Fluorometric microplate-based dimethoate assay using CdSe/ZnS quantum dots coated with a molecularly imprinted...

Area of Science:

• Analytical Chemistry
• Materials Science
• Environmental Science

Background:

• Accurate pesticide detection is crucial for environmental and food safety.
• Developing sensitive and selective analytical methods for pesticides like dimethoate is an ongoing challenge.
• Quantum dots (QDs) offer unique optical properties for sensing applications.

Purpose of the Study:

• To develop a sensitive and selective fluorometric assay for dimethoate determination.
• To utilize molecularly imprinted polymer (MIP)-coated CdSe/ZnS quantum dots (QDs) as a recognition probe.
• To establish a high-throughput microplate-based method for pesticide analysis.

Main Methods:

• Synthesis of MIP-coated CdSe/ZnS QDs via one-step reversed-phase microemulsion.
• Utilizing 3-aminopropyltriethoxysilane and tetraethoxysilane for MIP coating with dimethoate as template.
• Employing fluorescence quenching mechanism for dimethoate detection in a microplate format.

Main Results:

• The assay demonstrated linear fluorescence quenching with dimethoate concentration in the range of 5.0-150 μg L⁻¹.
• A low limit of detection of 2.1 μg L⁻¹ was achieved.
• Satisfactory recoveries (89.8%-98.0%) were obtained for dimethoate in spiked real samples.

Conclusions:

• The developed MIP-coated QD assay is rapid, cost-effective, sensitive, and selective for dimethoate.
• The microplate format enables simultaneous analysis of multiple samples, facilitating high-throughput screening.
• This method shows significant potential for practical application in pesticide monitoring.